In UMTS (Universal Mobile Telecommunications System) networks, attempts are made to adopt HSDPA (High Speed Downlink Packet Access) or HSUPA (High Speed Uplink Packet Access) for the purpose of improving frequency utilization efficiency and a peak data rate or the like to thereby make the most of features of W-CDMA (Wideband Code Division Multiple Access)-based systems. Regarding this UMTS network, Long Term Evolution (LTE) is being studied aiming at a higher frequency utilization efficiency, improvement of peak data rate and delay reduction or the like (Non-Patent Literature 1). Unlike W-CDMA, LTE uses an OFDMA (Orthogonal Frequency Division Multiple Access)-based scheme for downlinks as a multi-access scheme and uses SC-FDMA (Single Carrier Frequency Division Multiple Access)-based scheme for uplinks.
A signal transmitted over an uplink is mapped to appropriate radio resources and transmitted from a mobile terminal apparatus to a radio base station apparatus as shown in FIG. 1. In this case, user data (UE (User Equipment) #1, UE#2) is allocated to an uplink shared channel (PUSCH: Physical Uplink Shared Channel), and when transmitted simultaneously with user data, control information is time-multiplexed with PUSCH, and when only control information is transmitted, the control information is allocated to an uplink control channel (PUCCH: Physical Uplink Control Channel). The control information transmitted over this uplink contains downlink quality information (CQI: Channel Quality Indicator) and downlink shared channel retransmission response (ACK/NACK) or the like.
PUCCH typically adopts different subframe configurations for when transmitting CQI and ACK/NACK (FIG. 2A, FIG. 2B). In a PUCCH subframe configuration, seven SC-FDMA symbols are included in 1 slot (½ subframe). Furthermore, 1 SC-FDMA symbol includes 12 information symbols (subcarriers). To be more specific, in a CQI subframe configuration (CQI format) as shown in FIG. 2A, reference signals (RSs) are multiplexed with a second symbol (#2) and a sixth symbol (#6) in a slot, and control information (CQI) is multiplexed with other symbols (first symbol, third symbol to fifth symbol, and seventh symbol). Furthermore, in an ACK/NACK subframe configuration (ACK/NACK format) as shown in FIG. 2B, reference signals (RSs) are multiplexed with the third symbol (#3) to fifth symbol (#5) in a slot, and control information (ACK/NACK) is multiplexed with other symbols (first symbol (#1), second symbol (#2), sixth symbol (#6) and seventh symbol (#7)). In 1 subframe, the aforementioned slot is iterated twice. Furthermore, as shown in FIG. 1, PUCCH is multiplexed with radio resources at both ends of the system band and frequency hopping (inter-slot FH) is applied between two slots having different frequency bands within 1 subframe. The PUSCH subframe configuration includes seven SC-FDMA symbols in one slot.